The present invention relates to an improved electric safety device particularly concerning a device for sequentially controlling a power switch and a grounding switch of a high voltage electric device to render the user safe from a high voltage shock.
Electric power generated from a power station is distributed to consumers by means of high voltage current sent first through transmission lines to substations, then distributed to consumers. When a fault or problem occurs at a consumer distribution line, the maintenance person has to switch off the power source switch manually and then ground the switch for safety in processing his maintenance work. Such kind of manual switching off of the power source and grounding is dangerous if the remaining voltage is high enough and there may still remain enough voltage to harm or kill the maintenance person even though the power source has been switched off.